Intrinsic Mobility Limits of a Two-Dimensional Electron Gas in AlGaN/GaN Heterostructures

ABSTRACTWe present the results of a theoretical study of the 2D electron gas mobility at a AlxGa1−xN/GaN heterointerface. All standard mechanisms, including scattering by acoustic and optical phonons, and remote and background (residual) impurities have been included in our calculation of theoretical mobility limits in a AlxGa1−xN/GaN structure. Comparison of calculations with experimental mobilities obtained from high quality MOCVD grown Al0.15Ga0.85N/GaN heterostructures shows that the low temperature mobility in these samples is dominated by scattering from ionized impurities, with a smaller contribution from acoustic phonons.